This invention relates generally to the field of automation, and in particular to the use of automated equipment to transfer items. More specifically, the invention relates to the automated transfer of array cartridges into and out of an imaging apparatus.
1. Polymer Arrays
Methods for using arrays of polymers to identify receptors with specific affinities for one of the polymers in the array are known. For example, one method uses immobilized antibodies to analyze binding to peptide ligands or vice-versa. Another type of method uses immobilized oligonucleotides to analyze hybridization to a target nucleic acid. For instance, U.S. patent application Ser. No. 08/624,312, filed Mar. 26, 1996, the complete disclosure of which is herein incorporated by reference, describes apparatus and methods for carrying out repeated hybridizations of a target nucleic acid to an array of nucleic acid probes. Such polymer arrays are described in, e.g., U.S. Pat. No. 5,143,854 and published PCT Application Nos. WO90/15070 and WO92/10092, the complete disclosures of which are herein incorporated by reference. These polymer arrays are nucleic acid arrays which include a plurality of different polynucleotides coupled to a substrate in different known locations.
In one exemplary arrangement, such arrays are packaged within a housing or cartridge, like those described in, e.g., U.S. Pat. No. 5,945,334, and in copending U.S. patent application Ser. Nos. 08/624,312, previously incorporated by reference, 08/528,173, filed Sep. 19, 1995, and published PCT Application No. WO95/33846. The disclosures of all of these references are herein incorporated by reference. In brief, such a cartridge may be constructed of a body having a reaction cavity or hybridization chamber. The array or substrate is mounted over the cavity on the body such that the front side of the array substrate, e.g., the side upon which the polynucleotides are situated, is in fluid communication with the cavity. The cartridge includes inlet and outlet ports to allow various fluids to be introduced into and removed from the hybridization chamber.
2. Imaging
Imaging the polymer arrays may be accomplished, for example, by placing the cartridges into a scanning device, such as the GeneArray scanner, available from Affymetrix, Inc. Techniques for imaging polymer arrays are described in U.S. Pat. Nos. 5,834,758 and 5,578,832, the complete disclosures of which are herein incorporated by reference.
In many cases, it is desirable to maintain the cartridges in a temperature controlled environment. Hence, a need exists for equipment and techniques to transfer cartridges from a temperature controlled environment for placement into the scanner in an organized and efficient manner, and for the return of the cartridges to the temperature controlled environment following imaging. Hence, the invention is related to apparatus and methods to facilitate imaging of array cartridges in such a maimer.